KMP9 Gas Efficiency

[sniperelite7]

Search isn't yielding nothing!

Anyway, bought an old well used kmp9 and fixed it up. Shooting great so far. No hiccups and none of the quirks that tend to be associated with it. Gas efficiency is really bothering me though. Shooting full auto, or really quick semi with some rest in between gets me about 1-1 1/2 magazines worth of bb's before I need to recharge the gas(Propane).

Shooting very slowly, with maybe a minutes rest in between short bursts of semi, and it can give me 2 magazines worth before needing to refill. Temperature is usually 40-60f.

Whats bothering me is that this goes against some reviews where people where getting 2 mags on full auto. Or in the case of one user 4 magazines on full auto. Temperatures for them where around 40f.

So whats the average number of shots per fill one can expect from a kmp9 magazine? I just need a proper baseline that I can compare this old kmp9 too.

[CommieHunter]

The last one I tested (when they were still new) shot 3 full magazines on full auto and 5 magazines on slow-fire semi auto.

[Switchback]

Make sure you fill it right.

If you cool down the magazines, then fill them up, they'll need to warm back up. You should get at least 2 full magazines even outside.

[sniperelite7]

Thanks for the guys.

I typically filled the magazine by holding them at a slight angle, corrected that, and Filled it straight up and down, 3 second fills. How long total should it take to fill a kmp9 magazine?

Anyway, I filled a magazine and fired it, under what i'd consider skirmish. Use. Every so often a burst of auto. Mostly steady deliberate semi auto shooting, occasionally high tempo.

Was able to get 2 1/2 magazines worth before it finally died off. That sound about right?

Certainly way off from the 5 magazines CommieHunter said.

[Switchback]

Fill it until it stops making noise. Listen for a slow leak.

[DJ]

Another issue you are dealing with is simple laws of physics. This time of year (cold) you will get less pressure/volume. In the summer 70 degrees + and you will get the maximum psi volume of gas pressure. This is when you will get the advertised performance. Note when you see fps ads for guns it will typically state at what temperature the rating is performed. This time of year my KWA pistols will get 1+ mags of shooting, in Summer 2+. Don't sweat it too much, its perfectly normal, nothing to worry about. That is one of the drawbacks of GBB's.

[CommieHunter]

If you get 2 1/2 mags of intermediate burst fire, you're doing fine at this time of year. We tested ours when they first came out and it was like 69 or 70 F in the store.

[sniperelite7]

Hmm alright, thanks guys. Guess now all thats left is a low power bolt, and enjoying it. First airsoft gun that I ever had to wear hearing protection for!

[n5lyc]

I also have an kwa mp9, and use it year round. I love it.

in the winter i keep my spare mags inside my jacket to keep them somewhat warmer.
the mag in the gun just has to be air temp.

In the cooler months i can'd dump a full mag without noticing the cool down effects, and almost run out of gas before the mag is empty of bbs.

In short burst it is better, somewhat.

I love gobs, they make you learn trigger control.

I started off airsoft with HPA (high pressure air) jac's and went to aeg's and high caps, then went to mid caps in my aeg,but still carried 600+ rounds in a short game.

Now i carry a gas gun and about 150 - 200 rounds per game, and rarely use more than a mag.

The mp9's range and accuracy (helped with a eotech) is good for woodland (what we play most) and it is my primary most of the time.

I still dig out my classic army aeg, but love my kwa mp9.

The only problem with the mp9 is its size, i am a big guy, carrying a little gun.
It just don't look right, in a woodland setting.

Enjoy it, show the electric guys what propane is all about.

45 Bravo

[spazgar]

alright im having the same problems as sniperelite7 but its a lot warmer out now. i bought it used and very new at GBB. i just started to use propane and i was wondering where the lube goes on the mag? when i was test firing today it was either not feeding or double feeding and i had to clear the barrel. any help would be awesome. i love the KMP9 so much but kinda bummed but its okay cause i still need to learn a lot.

[spazgar]

also meant to ask if what mag pouches all you guys with the KMP9 use?

[Gator]

Not sure if this has already been done, But i plan to buy slightly larger mag pouches for my gas gun so i can fit hand warmers in the pouch with the mag.

[n5lyc]

Spagar, what brand of bbs are you using? And what weight?
Regular or biodegradable?

Also, how often do you lube the adapter?


I ask these questions because,
1. Use quality bbs.
2. The mp9 likes .25's at least.
3. If your bios are too old or have been subjected to too much humidity,
their dimensions and roundness may have been changed, like (I hate to mention the word) paintballs that are too old and have been exposed to air and are no longer round.

I say this because my mp9 and my classic army both like goldenball .25's when the bag is freshly opened.
But even sealing after each use, in about 4 months or so, I start having issues with both guns.
But open a new bag, and it is happy days again.
Same gun, same mag, same day, has to be something in the ammo

Also you can over lube the mp9.
It took me a while to figure that out.
Running green gas, no issues.
Run propane, and silicone after every 3/4 mags, issues.
I lube every 6 - 9 mags, and an occasional shot of silicone on the expansion chamber/ feeding nozzle when it sticks in the chamber when you pull the bolt back and it stays forward.

Maybe this will help shed a little light on your issues.

45 Bravo

[spazgar]

Damnit! I didn't even think of the BB size. Yeah I'm running .20s. Thanks a lot. Those other tips are also good for me. Yeah I'm a freak about not picking up spilt BBs off the ground or anything.

[n5lyc]

I didn't think anyone who would spend the money for a mp9 would use split or off the ground bbs.

I mean more along the lines of crosman or walmart .20's or .25's are no-no's


I mean using more along the lines of Elite force, ICS, Airsoft elite, or Goldenball. (in no particular order)

insert shameless plug here (www.bulkairsoftammo.com) has great prices, and good ammo.

also you can get sampler packs, includes 100 rounds each of different manufacturers,
to see which shoots best in your gun for $9
and you can get sampler weights, 100 rounds of each weight they sell for $9 shipped

100 rounds don't seem like much to some, but done right it is enough to see what shoots good in your gun.

just a suggestion or so.

keep us posted.

45 Bravo